Ok need to get better advise on this after the holiday but don't think a 2 pole can be changed into an 8 pole just by winding.
OK the stator has 24 slots but the rotor has to match.

Also at 8 pole you will get approx 5.700 revs at 400 hz and there will be a limit you can go to on hz before it all gets saturated or egg bound in technical terms.
One guy on another forum has just had a quote for a standard 3~ rewind at £350 I can supply him a new motor for £125